Tissue sealants are used to decrease or prevent the migration of fluid from or into a tissue. A well known material that has been used as a tissue sealant is "fibrin glue", which is typically made by contacting a solution or suspension of the blood protein fibrinogen with an enzyme or other reagent which will cause fibrin to crosslink. Typically, the enzyme thrombin is used, which cleaves the fibrinogen molecule at specific points to form fibrin monomer, which then spontaneously crosslinks. This is a natural reaction involved in the formation of blood clots. A familiar example of a crosslinked fibrin based material is a scab or an eschar. A disadvantage of fibrin glues is that they have little flexibility or extendibility once their deposition is complete. Moreover, fibrin can be biodegraded in a variable amount of time, depending on a number of uncontrolled parameters, and the duration of a fibrin based tissue sealant is not predictable. Adherence of fibrin clots to tissues can also be unpredictable.
As disclosed in PCT/US96/03834, synthetic materials can be used to make tissue sealants that exhibit high levels of tissue adherence, elastic compliance, and controlled biodegradability. Moreover, these synthetic sealants are completely free of viral and other biological hazards. However, synthetic sealants may not possess significant intrinsic hemostatic properties. Such properties are herein provided by the incorporation of hemostatic materials into one or more of the components of the sealant composition, in advance of or in concurrently with their application to tissue.